I specified dcerouter IP - host name in the /etc/hosts but it didnt' solve the problem. Moreover I grant access to Nokia770 to the pluto_main database. Also, when I run the Orbiter on the Maemo emulator I saw the same error message about unknown host but the Orbiter worked fine. Here is it log (from Maemo emulator):

I think I know what's wrong. Every message sent between devices are serialized. The first 4 bytes from the messages are a magic number like 1234. Well, it seems that your tablet uses low endian and the pc where the router is big endian. (in router's log I saw "Badly formed message")

A solution would be for you to go in src/SerializeClass/serializeclass.h and modify it (maybe add a #ifdef USE_LOW_ENDIAN) to reverse the order for bytes. Check the following functions:Write_unsigned_long, Write_long and Read_long. Then recompile Orbiter and test it on the tablet.